Adam did not think long about joining Eve, he fell into sin willingly, without any coercion from Satan or his wife.
“She took some of the fruit and ate, and she also gave some to her husband who was with her, and he ate.”
The mysterious phrase is “with her,” simple detective work places Adam at the scene of the crime, he was right next to Eve the whole time. Not only did he not stop her before it was too late, he jumped right in and took of the forbidden fruit. Once a happy couple living in bliss, now larger than life issues stare them in the face, and they suffer a complete breakdown in trust.
Adam chose not to trust God with a terrible choice. If he says “no” to his wife, he lives alone, uncertain whether God will make another Eve for him. If he says “yes” he forfeits divine favor, without knowing what that will entail.
Adam’s fall was painful and left God only one choice, God was going to have to engage in a divine rescue, unless he chose to permanently abandon humans, something his love could never do. The Trinity, namely Jesus, would need to become a man, and not only overcome Satanic temptation, but do so on the cross, and human death would finally die through his resurrection from the dead. The first Adam was head over the human race, that place was now lost, and Satan allowed to run free.
Jesus became the second Adam of a new human race, and those in the new birth enjoy power over the evil one.